A full-bandwidth acoustic frequency spectrogram viewer and lossless audio quality auditor for Linux supporting FLAC, WAV, MP3, Opus, Ogg Vorbis, M4A, and AAC. A lightweight Linux alternative to Spek for inspecting audio spectrograms, Nyquist rolloff shelves, and transcoded lossy files.

Key features powered by bundled FFmpeg:

• High-resolution dBFS acoustic spectrogram rendering with selectable scientific color palettes (Fiery, Viridis, Magma, Plasma, Intensity, Cool, Rainbow), adjustable dBFS dynamic range (60-160 dB), and combined or split stereo channel views.
• Real Hann-windowed Welch FFT spectral energy analysis measuring effective high-frequency shelf/cutoff (kHz), True Sample Peak (dBFS), RMS loudness, and Crest Dynamic Range (dB).
• Automatic lossless authenticity detection flagging low-bitrate lossy tracks upscaled or re-encoded into FLAC/WAV containers.
• 24-band spectral rolloff table and frequency-response chart across the full passband up to Nyquist (Fs/2).
• Batch Folder Lossless Quality Auditor with CSV audit export and annotated high-resolution PNG spectrogram report export.

Disclaimer: This project is an independent open-source tool and is not affiliated with, sponsored by, or endorsed by Alexander Kojevnikov or the Spek project.